Ochrobactrum Intermedium Research Articles

Isolation of Monocrotophos degrading bacterial consortium from agricultural soil for in vivo analysis of pesticide degradation.

Extensive Monocrotophos (MCP) application in agricultural soils has led to its ubiquitous accumulation in the environment. Human health can be adversely affected by chronic exposure to produce and water from such areas, causing endocrine dysfunction, birth defects, blood and nervous disorders. This study investigated the possibility of detecting Monocrotophos-degrading bacteria in soil samples taken from a cotton cultivation field in a local area. We isolated a consortium that could tolerate and neutralize Monocrotophos upto a concentration of 2000 ppm. The consortium on 16S rRNA sequencing were identified as Micrococcus luteus SBR2, Rhodococcus SBR5, Bacillus aryabhattai SBR8, Ochrobactrum intermedium SBK2. Significant tolerance of individual strains in the range of 500-5000 ppm was observed when incubating them in vitro with Monocrotophos in minimal salt medium. An analysis of the degrading genes opdA, mpd, and opd revealed plasmid borne opdA and mpd in the O.intermedium strain and B.aryabhattai strain. All the strains indicated genomic opdA and mpd whereas opd was not detected in plasmid or genomic DNA. The HPLC showed no peak at 2.5min, when individual strains were incubated with Monocrotophos. The HPLC analysis of soil samples incubated with the consortium for two weeks showed complete degradation of Monocrotophos. GC-MS analysis confirmed that Monocrotophos and its solvent cyclohexamide were degraded into non-toxic compounds such as cyclotrisiloxane compounds, acetic acid, and others. This study indicates that the expression of organophosphate hydrolyzing enzymes in the consortium can greatly contribute to the neutralization of organophosphorus compounds and also serve as a bioremediation method for agricultural soils.

Isolation, Characteristics, and Prospects of Using the Ochrobactrum Intermedium Strain in the Degradation of the Cypermethrin Pesticide

Isolation, Characteristics, and Prospects of Using the Ochrobactrum Intermedium Strain in the Degradation of the Cypermethrin Pesticide

Pneumonia due to Ochrobactrum intermedium in an ICU patient

Ochrobactrum intermedium is recognized as a rare emerging opportunistic pathogen mostly related with bloodstream infections. In this report, we describe the first clinical case of pneumonia due to O. intermedium. The case involved a 71-year old tetraplegic man hospitalized for vertebral fractures after falling from a ladder.

Bacterial biocontrol potential against Rigidoporus microporus: Hydrolytic enzyme activity and antibiotic inhibition

Rigidoporus microporus is a soil-borne pathogen that causes significant losses in rubber plantations worldwide. As an alternative technique, the development of bacteria as biological control agents capable of producing hydrolytic enzymes and antibiotics has emerged. The in vitro activity of bacterial isolates against R. microporus was assessed using hydrolytic enzyme production and antibiotic inhibition. The research included enzyme activity analyses and antagonism assays against R. microporus, followed by selection of the top ten isolates using the Analytical Hierarchy Process. The 16S rRNA gene sequencing was used to determine compatibility and identification. Twenty-two bacterial isolates produced one or more enzymes, including chitinase, glucanase, and cellulase. These isolates inhibited the growth of R. microporus through diffusible, volatile, and colonized soil, resulting to abnormal mycelial formation. Hierarchical analysis has selected 10 isolates with the highest potency and compatibility. Four isolates (S085, S108, SK909, and SK018) belonged to Serratia surfactantfaciens, while others were identified as Brucella intermedia (basonym: Ochrobactrum intermedium) (S018, T2, and BE60), Bacillus albus (NJ57), Bacillus amyloliquefaciens (P7), and Burkholderia cepacia (SS19.7). The present study demonstrated the ability of bacterial isolates to secrete hydrolytic enzymes and antibiotic metabolites causing permanent abnormalities in R. microporus mycelia, representing the first report of such metabolite activity of rhizosphere and endophytic bacteria as biological control agents against R. microporus. However, further study is needed to assess their performance under field conditions.

A-289 Emergence of Unusual Non-Fermentative Gram-Negative Bacilli Associated to COVID-19 Period at Brazilian Hospitals

Abstract Background Since the global pandemic of coronavirus disease (COVID-19), some studies have reported on the emergence of opportunistic nosocomial pathogens associated with co-infection on the outcome of COVID-19 patients. The aim of this study was to describe the increase of six unusual species of Non-fermentative Gram-negative bacilli (NF-GNB) clinical isolates recovered from inpatients in several Brazilian hospitals comparing pre-Covid-19 (January 2018 to December 2019) period vs Covid-19 (January 2020 to December 2021) period. Methods This study design was a retrospective, observational analysis based on microbiological data of emergent NF-GNB isolates, detected in several Brazilian tertiary hospitals. The bacterial identification was performed by Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF/MS) and the susceptibility of antibiotics was determined using disk diffusion method. Results During the 48 months period, a total of 1665 (2018; 349), (2019; 351), (2020; 485), (2021; 480) emergent NF-GNB isolated from blood (n = 744), respiratory tract (n = 239), skin and soft tissue (n = 264); urine (n = 119), catheter (n = 101), fluid and secretions (n = 113), Cerebrospinal fluid (n = 12) and others (n = 73) were analyzed. The frequency of NF-BGN according to species level identification was Stenotrophomonas maltophilia (1040; 62.5%), Burkholderia cepacea complex (457; 27.4%), Elizabethkingia meningoseptica (64; 3.8%), Elizabethkingia miricola (31; 1.8%), Ochrobactrum anthropi (69; 4.1%) and Ochrobactrum intermedium (4; 0.2%). The prevalence of these NF-BGN detected in pre-Covid-19 period (2018–2019) and Covid-19 period (2020–2021) were 42% and 58%, respectively. The incidence of Stenotrophomonas maltophilia, Burkholderia cepacea complex, Elizabethkingia spp. and Ochrobactrum spp. infection was (47.7% and 52.3%), (42.9% and 57.1%), (43.2% and 56.8%) and (50.7% and 49.3%) among female and man patients, respectively. For Stenotrophomonas maltophilia, Burkholderia cepacea complex and Ochrobactrum spp. the main age range was over 60 years (44.5%, 44.9% and 42.5%) while for Elizabethkingia spp. the main age range was 0–10 years of age with 42.5% of cases in the pre-COVID-19 period and over 60 years old with 43.9% in the COVID-19 period. Compared the two periods (2018–2019 vs 2020–2021) for Stenotrophomonas maltophilia the resistance rate to levofloxacin and sulfamethoxazole-trimethoprim was (3.9% vs 4.6%) and (4% vs 4.2%), respectively. Conclusion Our data point to a scenario wherein the presence of opportunistic pathogens may have been intensified by the covid-19 pandemic. Further studies should be carried out to clarify these findings.

Comparison of automatic methods MALDI-TOF, VITEK2 and manual methods for the identification of intestinal microbial communities on the example of samples from alpacas (Vicugna pacos).

Universally, in microbiological diagnostics the detection of live bacteria is essential. Rapid identification of pathogens enables appropriate remedial measures to be taken. The identification of many bacteria simultaneously facilitates the determination of the characteristics of the accompanying microbiota and/or the microbiological complexity of a given environment. The effectiveness of the VITEK2 Compact automated microbial identification system and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS), analytical profile index (API) and Remel RapID tests were compared in identification of bacteria isolated from the alpaca gastrointestinal tract. Most isolates were Gram-positive, such as Bacillus cereus, Bacillus flexus, Bacillus licheniformis, Bacillus pumilus and Bacillus subtilis; Enterococcus faecium, Enterococcus gallinarum, Enterococcus hirae and Enterococcus casseliflavus; Staphylococcus aureus, Staphylococcus equorum, Staphylococcus lentus, Staphylococcus pseudintermedius and Staphylococcus sciuri; Paenibacillus amylolyticus; Cellulosimicrobium cellulans; Leuconostoc mesenteroides; Clostridium perfringens; Corynebacterium stationis, Corynebacterium xerosis, and Corynebacterium diphtheriae (the last only isolated manually by API Coryne and the VITEK2 system and Corynebacteria (CBC) card). Corynebacterium diphtheriae was misidentified by MALDI-TOF MS as Candida lipolytica (currently Yarrowia lipolytica). Gram-positive and Gram-variable Micrococcus luteus were also isolated. Gram-negative Enterobacter cloacae, Enterobacter gergoviae, Enterobacter hormaechei and Enterobacter ludwigii; E. coli; Klebsiella pneumoniae subsp. pneumoniae; Citrobacter braakii and Citrobacter freundii; Serratia liquefaciens, Serratia odorifera and Serratia marcescens; Morganella morganii subsp. morganii; Providencia alcalifaciens; Pseudomonas aeruginosa; Stenotrophomonas maltophilia; Moraxella osloensis; and Ochrobactrum intermedium were also found. The yeasts Candida albicans, Candida haemulonii and Candida ciferrii were also present. MALDI-TOF MS enabled the identification of pathogens and opportunistic pathogens from the alpaca gut which may represent a high risk to human and animal health.

Effect of Electro-Oil Acclimation of an Indigenous Strain on the Performance of Sediment Microbial Fuel Cells (SMFC)

Sediment microbial fuel cell (SMFC) is a type of MFC without a proton exchange membrane. However, SMFC have had problems with low-power production performance. In this paper, the effects of native bacteria (K1) in oily sludge and their electro-oil-induced domestication on the power generation and oil removal performance of SMFC were studied. The results showed that K1 belonged to Ochrobactrum intermedium. During the domestication process, an upward trend was shown in the OD600 and ORP values in the culture medium, and it grown best at 0.7 V. Ochrobactrum intermedium K1 significantly increased the average output voltage, electromotive force, and maximum power density of SMFC and reduced the apparent internal resistance of the battery. The maximum power density was 169.43 mW/m3, which was 8.59 times higher than that of the control group. Ochrobactrum intermedium K1 improved the degradation of crude oil by SMFC. Ochrobactrum intermedium K1 enhanced the degradation of high-carbon alkanes and even-carbon alkanes in n-alkanes. Cyclic voltammetry and chronoamperometry tests showed that after acclimation, Ochrobactrum intermedium K1 improved the extracellular electron transfer efficiency (EET) mediated by c-Cyts and flavin by increasing the surface protein redox potential.

Effect of noble bacteria Ochrobactrum intermedium (Alhpa-22) on decolorization of methyl orange dye in a bioreactor

Abstract In this study Ochrobactrum intermedium (Alhpa-22) was isolated from petroleum refinery sludge and characterized by using 16rRNA. In experimentation, for decolrization of methyl orange dye an indigenous noble bacterial ochrobactrum intermedium (Alhpa-22) at 35 °C has been used in a bioreactor. The ochrobactrum bacterial decolorized methyl orange dye having the concentration of 50 mgL−1 by 87 % within 9 days, which is a very encouraging result. decolorization of methyl orange dye by the isolated bacteria was elucidated using a UV–Vis spectrophotometer. The experimental data were fitted first and zero order kinetics models which show degradation of dye follows first order kinetics in presence of Lysinibacillus fusiformis KLm1, bacterial ochrobactrum intermedium (Alhpa-22) and mix consortia of Lysinibacillus fusiformis KLm1 and ochrobactrum intermedium (Alhpa-22). The rate constant were estimated to be 0.017 h−1, 0.020 h−1 and 0.014 h−1 respectively. Due to its higher decolorizing capability these may be used for the bioremediation of methyl orange dye (azo dye).

Immune evasion through Toll-like receptor 4: The role of the core oligosaccharides from α2-Proteobacteria atypical lipopolysaccharides

Lipopolysaccharides (LPS) are major players in bacterial infection through the recognition by Toll-like receptor 4 (TLR4). The LPS chemical structure, including the oligosaccharide core and the lipid A moiety, can be strongly influenced by adaptation and modulated to assure bacteria protection, evade immune surveillance, or reduce host immune responses. Deep structural understanding of TLRs signaling is essential for the modulation of the innate immune system in sepsis control and inflammation, during bacterial infection. To advance this knowledge, we have employed computational techniques to characterize the TLR4 molecular recognition of atypical LPSs from different opportunistic members of α2-Proteobacteria, including Brucella melitensis, Ochrobactrum anthropi, and Ochrobactrum intermedium, with diverse immunostimulatory activities. We contribute to unraveling the role of uncommon lipid A chemical features such as bearing very long-chain fatty acid chains, whose presence has been rarely reported, on modulating the proper heterodimerization of the TLR4 receptor complex. Moreover, we further evaluated the influence of the different oligosaccharide cores, including sugar composition and net charge, on TLR4 activation. Our studies contribute to elucidating, from the molecular and biological perspectives, the impact of the α2-Proteobacteria LPS cores and the chemical structure of the atypical lipid A for immune system evasion in opportunistic bacteria.

The degradation of chicken feathers by Ochrobactrum intermedium results in antioxidant and metal chelating hydrolysates and proteolytic enzymes for staphylococcal biofilm dispersion.

The increase in the generation of chicken feathers, due to the large production of the poultry industry, has created the need to search for ecologically safer ways to manage these residues. As a sustainable alternative for recycling keratin waste, we investigated the ability of the bacterium Ochrobactrum intermedium to hydrolyze chicken feathers and the valorization of the resulting enzymes and protein hydrolysate. In submerged fermentation with three different inoculum sizes (2.5, 5.0, and 10.0mg of bacterial cells per 50mL of medium), the fastest degradation of feathers was achieved with 5.0mg cells, in which a complete decomposition of the substrate (96h) and earlier peaks of keratinolytic and caseinolytic activities were detected. In the resulting protein hydrolysate, we noticed antioxidant and Fe2+ and Cu2+ chelating activities. ABTS scavenging, Fe3+-reducing ability and metal chelating activities of the fermentative samples followed the same trend of feather degradation; as feather mass decreased in the media, these activities increased. Furthermore, we noticed about 47% and 60% dispersion of established 7-day biofilms formed by S. aureus after enzymatic treatment for 5h and 24h, respectively. These findings highlight the potential use of this bacterium as an environmentally friendly alternative to treat this poultry waste and offer valuable products.

In Vitro Studies of Nanoparticles as a Potentially New Antimicrobial Agent for the Prevention and Treatment of Lameness and Digital Dermatitis in Cattle

Digital dermatitis (DD) is the second most prevalent disease in dairy cattle. It causes significant losses for dairy breeders and negatively impacts cows' welfare and milk yield. Despite this, its etiology has not been entirely identified, and available data are limited. Antibiotic therapy is a practical method for managing animal health, but overuse has caused the evolution of antibiotic-resistant bacteria, leading to a loss in antimicrobial efficacy. The antimicrobial properties of metal nanoparticles (NPs) may be a potential alternative to antibiotics. The aim of this study was to determine the biocidal properties of AgNPs, CuNPs, AuNPs, PtNPs, FeNPs, and their nanocomposites against pathogens isolated from cows suffering from hoof diseases, especially DD. The isolated pathogens included Sphingomonas paucimobilis, Ochrobactrum intermedium I, Ochrobactrum intermedium II, Ochrobactrum gallinifaecis, and Actinomyces odontolyticus. Cultures were prepared in aerobic and anaerobic environments. The viability of the pathogens was then determined after applying nanoparticles at various concentrations. The in vitro experiment showed that AgNPs and CuNPs, and their complexes, had the highest biocidal effect on pathogens. The NPs' biocidal properties and their synergistic effects were confirmed, which may forecast their use in the future treatment and the prevention of lameness in cows, especially DD.

Carbonyl Cyanide 3-Chloro Phenyl Hydrazone (CCCP) Restores the Colistin Sensitivity in Brucella intermedia.

Brucella intermedia (formerly Ochrobactrum intermedium), a non-fermentative bacterium, has been isolated from animals and human clinical specimens. It is naturally resistant to polymyxins, including colistin (CO), and may cause opportunistic infections in humans. We isolated six Brucella intermedia strains from Senegalese monkey stool. In order to determine whether an efflux pump mechanism was involved in CO resistance in B. intermedia, we evaluated the effects of verapamil (VRP), reserpine (RSP), phe-arg β-naphthylamide dihydrochloride (PAβN) and carbonyl cyanide 3-chloro phenyl hydrazone (CCCP), four efflux pump inhibitors, on these colistin-resistant strains. Using the broth microdilution method, a CO and CCCP combination of 2 µg/mL and 10 µg/mL, respectively, significantly reduced the CO minimal inhibitory concentration (MIC) of B. intermedia, supporting an efflux pump mechanism. In contrast, VRP, PAβN and RSP did not restore CO susceptibility. A time kill assay showed a bactericidal effect of the CO-CCCP combination. Genomic analysis revealed a potential implication in the CO resistance mechanism of some conserved efflux pumps, such as YejABEF, NorM and EmrAB, as previously reported in other bacteria. An inhibitory effect of the CO-CCCP combination was observed on biofilm formation using the crystal violet method. These results suggest that the intrinsic CO resistance in Brucella intermedia is linked to an efflux pump mechanism and that the synergistic effect of CO-CCCP may open a new field to identify new treatments to restore antibiotic efficacy in humans.

Molecular identification and characterization of indigenous bacterial strains isolated from soils around some oil refineries in Iran

One of the main causes of soil pollution is the release of crude oil into the environment. Indigenous microorganisms with the capability of biodegrading hydrocarbon components can be used to improve the efficiency of microbial bioremediation technology. Here, oil-contaminated soils were collected from five oil refineries (Abadan, Isfahan, Tehran, Tabriz and Shiraz) for screening and isolation of geographically adaptive indigenous oil-degrading bacteria. Bacterial colonies from oil-contaminated soil samples were isolated, which were able to grow in a medium containing crude oil, light, and heavy diesel, as a sole carbon source. Twelve strains were isolated, purified, and identified, using the 16S rRNA gene sequencing analysis. The isolates belonged to five species, including Achromobacter spanius, Klebsiella quasipneumoniae, Ochrobactrum intermedium, Citrobacter amalonaticus, Pseudomonas aeruginosa. These bacterial strains were capable of growing in media containing crude oil, light and heavy diesel for 7 to 9 days and had the potential for biosurfactant production. These bacterial strains can be considered as geographically adaptive bacteria, creating preliminary data for further research to utilize their bioremediation potential.

Experimental study on wax removal and viscosity reduction of waxy crude oil by Ochrobactrumintermedium

To investigate the influence of microbial wax removal and viscosity reduction technologies on the fluidity of waxy crude oil, this study took the waxy crude oil from China's Daqing Oilfield as the experimental object for microbial wax removal and viscosity reduction experiment. First, utilizing standard strain screening and culture protocols, a high-efficiency microbial strain H-1 (Ochrobactrum intermedium) was proposed from in situ soil. The single factor experiment and multi-factor response surface analysis were then utilized to optimize the temperature, initial pH value of the medium, and NaCl mass concentration needed for the strain's growth. Oil displaced activity and emulsification tests were used to evaluate the biosurfactants produced by the metabolism of strain H-1, and Fourier transform infrared spectroscopy was used to identify the types of biosurfactants. Finally, the application effect of strain H-1 on wax removal and viscosity reduction of waxy crude oil were clarified through the wax crystal morphology, wax content, and viscosity of waxy crude oil. The research findings indicated that strain H-1 produced best at a temperature of 38.5 °C, pH value was 7.1 and the mass fraction of NaCl was 0.64%. The lipopeptide biosurfactant produced by strain H-1 can displace oil. Additionally, strain H-1 has a high emulsifying capacity, with a 61.25% emulsifying coefficient. After 7 days of treatment with the strain H-1, the wax crystal morphology of the waxy crude oil changed from a large-sized aggregated to a small-sized sparse condition, and the wax content of the waxy crude oil fell by 38.67%. The viscosity reduction rate of strain H-1 to waxy crude oil was consistently greater than 30% over the temperature range of 30–42 °C, with the greatest rate of 42.38% at 39 °C. The preceding results demonstrate that strain H-1 can degrade the wax components of waxy crude oil, lower the crude oil's low temperature viscosity, and then improve the crude oil's low-temperature fluidity.

Antimicrobial and Antibiofilm Activities of Bacterial Strain P-6B from Segara Anakan Against MRSA 2983

Methicillin-resistant Staphylococcus aureus (MRSA) infection has become a worldwide concern due to the increasing MRSA resistance to antibiotics. This condition encourages the continuous exploration of new anti-MRSA compounds. Thus, this study explored the effect of carbon (starch, glucose, sucrose, lactose) and nitrogen (casein, yeast extract, urea, peptone) sources for the fermentation medium to produce antibacterial and antibiofilm compounds from bacterial strain P-6B against MRSA 2983. The results showed that six-day incubation produced bioactive extracts with the highest antimicrobial activity (11.361 ± 0.860 mm) and the highest activity to inhibit biofilm formation (89.159 ± 0.293% %). In comparison, three-day incubation produced a bioactive extract with the highest activity to degrade biofilm (86.450 ± 3.260%). Glucose was the best carbon source to produce an extract with antibacterial and biofilm inhibition activities. However, starch was the best carbon source to produce an extract with biofilm degradation activity. Urea was the best nitrogen source to produce extracts with antimicrobial and antibiofilm activities. Species identification based on the 16S rRNA gene revealed a 99.78% similarity with Ochrobactrum intermedium strain NBRC 15820 (NR_113812.1). These findings suggested the potency of Ochrobactrum P-6B from Segara Anakan Cilacap as indigenous sources of bioactive compounds with anti-MRSA activities.

Genotoxicity assessment of textile waste contaminated soil and characterization of textile dye degradation by a novel indigenous bacterium Ochrobactrum intermedium BS39

The harmful effects of textile wastewater irrigation practices on the crop productivity and soil nutrient levels are primarily related with the accumulation of recalcitrant azo dyes in the soil. Therefore, toxicity assessment of the textile waste contaminated soil along with the development of a powerful soil bioremediation strategy is a challenging task for the researchers. Present study aimed to evaluate potential toxicity of the textile wastewater irrigated soil collected from Panki industrial site 5, Kanpur, India employing Ames Salmonella/mammalian microsome test, Escherichia coli DNA repair defective mutation assay and Allium cepa chromosomal aberration assay. The results of the Ames test and DNA repair defective mutation test showed that all the organic extracts of the contaminated soil samples induced different degrees of DNA damage, indicating the existence of mutagenicity and genotoxicity. Additionally, in A. cepa root cells, the contaminated soil altered mitotic index and caused chromosomal abnormalities. Results of the study demonstrated potential health risks related with the irrigation of textile wastewater. Keeping in view of the above scenario, the study led to the isolation and characterization of a novel indigenous bacterium capable of tolerating very high concentration of reactive black 5 dye (500 μg-mL−1) and salt (20 gL-1) with concurrently high efficiency of the dye degradation i.e., 93% decolorization at temperature of 37 °C and in pH range of 5–9. Based on the 16S rRNA gene sequencing, the bacterium was identified as Ochrobactrum intermedium. Further, dye degradation products were identified as sodium-2-hydrosulfonylethyl sulphate and sodium-3-aminonaphthalene-2-sulfonate by Gas Chromatography-Mass spectrometry; and this isolate can be exploited for bioremediation of textile waste contaminated soils.

The potential of endophytic bacteria to suppress bacterial leaf blight in rice plants

Abstract. Rahma H, Nurbailis, Busniah M, Kristina N, Larasati Y. 2021. The potential of endophytic bacteria to suppress bacterial leaf blight in rice plants. Biodiversitas 23: 775-782. Endophytic bacteria are potential as biocontrol agents against bacterial leaf blight (BLB) disease caused by Xanthomonas oryzae pv. oryzae in rice to support sustainable agriculture. This study aimed to select and characterize 22 endophytic bacteria isolated from healthy rice, determine their ability to promote plant growth and suppress bacterial leaf blight disease in rice and also identify potential endophytic bacterial isolates. The study was arranged in a Completely Randomized Design with 24 treatments and three repetitions. The treatments used in the current study consisted of Xanthomonas oryzae infected plants and treated with endophytic bacterial isolates; infected plants without endophytic bacteria treatment (positive control), non-infected plants (negative control). Identification of potential endophytic bacteria was performed based on 16S rRNA sequences. Three out of 22 bacterial isolates, i.e., LmB1, LmA6, and LmB2 were able to suppress bacterial leaf blight disease with severity levels of 35.82%, 23.78%, and 23.78%, respectively. Based on the rice plant growth parameters, three bacterial isolates (LmA6, LmB1, and LmB35) were able to increase the growth of rice plants with an average value of 69.56%, 56.51%, and 47.82%, respectively. Two bacterial isolates, i.e., LmB 1 and LmA6 suppress the development of bacterial leaf blight disease and increase the growth of rice plants. Based on DNA sequence comparisons of DNA fragments amplified by 16S rRNA related marker of the selected bacterial isolates and database, then LmA6, LmB2, LmB1, and LmB35 had similarities with Bacillus cereus MD152 (96.87%), Bacillus thuringiensis ATCC 10792 (98.20%), Ochrobactrum intermedium strain OI1 (97.52%), and Stenotrophomonas maltophilia strain A1w2 (97.92%), respectively. Our study revealed that the indigenous endophytic bacteria from rice plants could be potential biological agents for controlling bacterial leaf blight disease and increasing plant growth.

Induction of TLR4/TLR2 Interaction and Heterodimer Formation by Low Endotoxic Atypical LPS.

The Toll-like receptor 4 (TLR4)/myeloid differentiation protein-2 (MD-2) complex is considered the major receptor of the innate immune system to recognize lipopolysaccharides (LPSs). However, some atypical LPSs with different lipid A and core saccharide moiety structures and compositions than the well-studied enterobacterial LPSs can induce a TLR2-dependent response in innate immune cells. Ochrobactrum intermedium, an opportunistic pathogen, presents an atypical LPS. In this study, we found that O. intermedium LPS exhibits a weak inflammatory activity compared to Escherichia coli LPS and, more importantly, is a specific TLR4/TLR2 agonist, able to signal through both receptors. Molecular docking analysis of O. intermedium LPS predicts a favorable formation of a TLR2/TLR4/MD-2 heterodimer complex, which was experimentally confirmed by fluorescence resonance energy transfer (FRET) in cells. Interestingly, the core saccharide plays an important role in this interaction. This study reveals for the first time TLR4/TLR2 heterodimerization that is induced by atypical LPS and may help to escape from recognition by the innate immune system.

Deciphering Cadmium (Cd) Tolerance in Newly Isolated Bacterial Strain, Ochrobactrum intermedium BB12, and Its Role in Alleviation of Cd Stress in Spinach Plant (Spinacia oleracea L.).

A cadmium (Cd)–tolerant bacterium Ochrobactrum intermedium BB12 was isolated from sewage waste collected from the municipal sewage dumping site of Bhopal, India. The bacterium showed multiple heavy metal tolerance ability and had the highest minimum inhibitory concentration of 150 mg L–1 of Cd. Growth kinetics, biosorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Fourier transform infrared (FTIR) spectroscopy studies on BB12 in the presence of Cd suggested biosorption as primary mode of interaction. SEM and TEM studies revealed surface deposition of Cd. FTIR spectra indicated nitrogen atom in exopolysaccharides secreted by BB12 to be the main site for Cd attachment. The potential of BB12 to alleviate the impact of Cd toxicity in spinach plants (Spinacia oleracea L.) var. F1-MULAYAM grown in the soil containing Cd at 25, 50, and 75 mg kg–1 was evaluated. Without bacterial inoculation, plants showed delayed germination, decrease in the chlorophyll content, and stunted growth at 50 and 75 mg kg–1 Cd content. Bacterial inoculation, however, resulted in the early germination, increased chlorophyll, and increase in shoot (28.33%) and root fresh weight (72.60%) at 50 mg kg–1 of Cd concentration after 75 days of sowing. Due to bacterial inoculation, elevated proline accumulation and lowered down superoxide dismutase (SOD) enzyme activity was observed in the Cd-stressed plants. The isolate BB12 was capable of alleviating Cd from the soil by biosorption as evident from significant reduction in the uptake/translocation and bioaccumulation of Cd in bacteria itself and in the plant parts of treated spinach. Potential PGP prospects and heavy metal bioremediation capability of BB12 can make the environmental application of the organism a promising approach to reduce Cd toxicity in the crops grown in metal-contaminated soils.

Ochrobactrum intermedium Bacteraemia in COVID-19 Positive Patients: Case Report of Rare Co-infection from Northern India

Ochrobactrum intermedium (O. intermedium) is a novel emerging gram negative bacillus infecting immunocompromised hosts. It is known for its multidrug resistance and to distinguish it from other species of Ochrobactrum genus by conventional methods, is often difficult. Here, authors report two unusual and interesting cases of bacterial infection due to O. intermedium in a 28-yearold female and 46-year-old male having Coronavirus Disease-2019 (COVID-19) infection. Rapid identification by Matrix Assisted Laser Desorption/Ionisation-Time Of Flight (MALDI-TOF) mass spectrometry and patient’s treatment guided by antibiotic sensitivity yielded in favourable outcome. Present report describes clinical and microbiological characteristics of this rare pathogen and also highlights the need of automated methods for proper identification of such opportunistic pathogens and their unique antibiotic susceptibility profiles.